"Rob very much resents Chyna," said the source. "He thinks she is evil. But for his daughter's sake, he plans on staying calm."

Calm as in 'not posting any more revenge porn of his ex whenever he gets angry'? Because yeah, that's probably a good idea.

The exes have yet to reach a custody arrangement and Rob was reportedly "basically told to shut up and lay low until he and Chyna come to an agreement."

"Rob is listening to advice from his family and instructions from his lawyer to behave," the source said, adding, "Everyone wants him to be quiet and not get into any more trouble. He isn't happy about going to court, but he also isn't agreeing with Chyna's demands."

The source also revealed that Rob's past behavior could cost him.

"There have been concerns that he will lose custody," they explained. "He just can't act mental on social media. It could be devastating for him."

Chyna and Rob are scheduled to meet in court on September 18. Says Chyna's lawyer Lisa Bloom, "We look forward to proving our case at that time."